Light-weight girder



Patented Oct. 26,1926.

UNITED STATES PATENT OFFICE.

CLAUDE DORNIER, OI FRIEDBIOESHAIEN, GERMANY, ASBIGNOR TO THE FIRE: LUI'TSCHIFFBAU ZEPPELIN GESELLBCHAFT MIT BESCKBANKTEB HAI'TUNG, OI

FRIEDBICHSHAFEN, GERMANY.

LIGHT-WEIGHT GIRDEB.

Application illed June 88, 1820, Serial No. 392,583, and in Germany In 4, 1917.

(GRANTED UNDER- m PROVISIONS 01' THE ACT OF KARO! 3, 1921, 41 STATE. L, 1818.)

My invention refers to girders which combine small weight with reat strength and can be manufactured witfi ease, so that they are suitable for wholesale manufacture more especially for the purpose of air craft construction.

In the novel girder, which is preferably made of light metal, a middle web of sheet metal bent in zigzaa fashion has its longitudinal edges rigidly fixed to flange plates extending vertically in regard to the surface of the middle web. The width of the flange plates does not materially exceed the depth of the corrugations formed in the middle web which is thus easily accessible from both sides and in this way distinguishes favorably from girders whose webs consist of a row of adjoining cells. Besides, it braces the flange plates in a most effective manner and the danger of buckling and'bending is thus effectually avoided. I

The drawings attached to this specification and forming part thereof illustrate two modifications of a girder embodying my invention by way of example.

Fig. 1 is a perspective view of aplate girder with plane flange plates and Fig. 2 is a similar view of a girder with corrugated flange plates, the parts being shown unassembled. In the modification'shown in Fig. 1 the middle web is formed by a thin corrugated sheet metal strip at having its lateral edges provided with tongues b deflected at right angles to said strip a. plane flange plates 0 being fixed to the tongues b by riveting or welding. 1

In the modification illustrated in Flg. 2

(I is the zigzag-shaped sheet metal strip forming the middle web. f, 'f are the top and bottom flange plates each of which is braced by two longitudinal grooves g. An-

gle strips e, e are riveted or otherwise secured to both sides of the middle web (1 so as to laterally project above and below it, respectively, an the flange plates f are secured .by riveting or otherwise to the outer surfaces of the angle strips e. At the ends the girder is reinforced by means of strong plates h extending between and fixedto the angle stri s on each side of the middle web.

Prefera 1y, thin steel plate or light metal sheetis employed. but it is also possible to produce girders which at least artially consist of wood, cellulose or other artificial products. According to the constructional material employed, the various parts of the girder can also be united with each other by gluing or bolting or in similar manner.

I wish it to be understood that I do not desire to be limited to the exactdetails of construction shown and described, for obvious. modifications will occur to a person skilled in the art.

I claim 1. In a composite sheet metal girder in combination, two sheet metal plates disposed parallel, a separate sheet metal web bent zi zag fashion arranged intermediate said plates and angle strips fixed to said web and to said plates, respectively.

In testimony whereof I. afiix signature.

CLAUDE DORNIER. 

